[ubuntu] Modem issues when switching to win xp

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http://ubuntuforums.org – Hey, so i have linux 10 and 11, both on the same HDD, but partitioned twice. I wanted to get rid of 11, so i installed win xp on it instead of 11 but i could not connect to any Internet at all. The wifi didnt work, so i plugged in the modem, but it still didnt connect. It seems as win xp couldn't recognize it at all. The laptop is an acer aspire 3680. Im not sure, but is it because of the software modem option in "additional drivers" I activate it in ubuntu 10, so maybe thats why it didnt work in win xp? not sure, but can someone help me out? thanks (Hardware)